Apparatus for sampling



Filed June 23, 1931 4 Sheets-Sheet 1 7 llfVEgTOR I Nov. 12, 1935. T. THORSTEN APPARATUS FOR SAMPLING Filed June 25, 1931 4 Sheets$heet "r. .THbRsTEN APISARA'I'US FOR SAMPLING Nov. 12, 1935.

Filed June 25, 1931 4 Sheets-Sheet s INVENTORVQ T. THORSTEN APPARATUS FOR SAMPLING Nay. 12, 1935.

Filed Jun 23, 1931 4 Sheets-Sheet 4 representative samples Patented Nov.

This invention relates to the sampling of ma- PATENT OFFICE 2,020,529 APPARATUS FOR SAMPL1NG Thorleif Thorsten, Pittsburgh, Pa. Application June 23, 1931, Serial No. 546,282

V 19 Claims. (or. 73-21) terials and is especially concerned with the removal of a sample from a fluid stream.

Various types of materials in a finely divided state are conveyed in a current of air through a pipe or other conduit. For instance, powdered coal is frequently 'tr ansported from one place to another suspended in acurrent of air.

For various reasons it is desirable to select of the material being conveyed. For instance, with powdered coal it is desirable to secure samples order that its quality may of the coal, first, in be determined; and

secondly, in order that thefineness of the crushing may be ascertained; and thirdly, in order that it can. be determined whether the boiler is being operated at the coal being burned. terials also have to highest efilciency with the Other finely pulverized'mabe sampled, as for instance,

7 flour and various finely divided mineral materials, as for exampl'e, cement.

When suspended along by a r different points, dep

particles are being carried fluid current stratification'occurs at ending upon the presence of curves in theconveyor pipe or conduit, the presence of obstructions, and other causes.

For instance, in some cases there may be some stratiflcation caused by the action of gravity. In other cases the air may rotate at a considerable speed,

tending to cause the heavier particles to be thrown against the outer walls of the conduit. In still other cases a bend in the pipe or conduit may cause Stratification due to the greater inertia of 5 larger or heavier particles over that of smaller and lighter particles.

According to the ra tus for sampling is provided according present invention an appato which a truly representative sample may be obtained under any condition of stratification of the material.

The invention may reference to the which Figure l mechanism invention;

accompanying drawings in Figure 2 represents a horizontal section in the plane of line 11-11 hrough the sample stallation;

Figure 3 is a vertical section on a of Figure 1;

larger scale selecting element of the in- Figure 4 is a section in the plane of line IV-IV of Figure 3 showing elevation;

the sample selecting unit in Figure 5 is a horizontal section in the plane of line V--V of Figure scale;

Figure 6 is view 3, the view being on a larger similar to Figure 1 showing the sampling mechanism built into a pipe 5e6- 0 tion especially adap ted to receive it;

' chamber 9 therein.

be readily understood by,

V outer end so that the passageway I9 is of out- Figure 7 is a view similar to Figure 1 wherein the sample is discharged into a difierent type of receiving container;

Figure 8 is a section of collector arm;

Figure 9 is a front elevation of the arm shown in Figure 8;

Figure 10 is a view similar to Figure 9 of still a further modification; and

Figure 11 represents a. section, more or less 10 diagrammatic, of a sample collector provided for grading of the sample.

In the drawings, l designates a conduit or pipe through which a fluid is adapted to be conveyed, the fluid travelling in the direction of the arrow shown in the drawings. For the purpose of describing the invention, it may be assumed that the fluid is a gaseous fluid, more particularly a through a modified form a current of air, and that it is carrying suspended solid particles, say for instance, powdered coal.

The sample removing unit is designated generally by. the reference numeral 2. It comprises a vertical post 3 having the front portion thereof stream-lined as indicated at 4, and as shown in Figure 5. Within the post 3 is a vertical passageway 5. The post also has a vertically extending bore or hole 6 therein in which is a vertically extending rotatable shaft 1. At the top of the post is a head portion 8 having a hollow The top of the shaft 1 extends into this chamber and is provided with a bevel gear'lO thereon. Journalled in the head portion 8 is a hub member ll having a shaft 12 thereon, the shaft [2 being provided with a bevel gear l3 meshing with the bevel gear Ill. The arrangement is such that upon rotation of the shaft 6 the shaft I2 .with its attached hub II will be rotated. The sample selecting element is rotated by means of this hub.

This sample selecting element comprises a radial arm l4 having a sleeve portion l5 thereon extending at right angles thereto, this sleeve portion being hollow and being attached to the hub II. The sleeve portion l5 has'a bearing in the head portion 8 at points l6 and Il. Between the bearing portions l6 and I! the sleeve portion I5 is provided with an annular series ofv openings 18 through which fluid may flow from the interior of the sleeve l5 into the vertical passage 5 5 within the post 3.

The arm [4 is also stream-lined, and has a passageway: is extending throughout its length, this passageway leading into the interior of the sleeve portion [5. The arm tapers toward its wardly diminishing cross-section. In the radial edge of the arm M on the side thereof toward the post 3 so as to open toward the stream of fluid, is a slot 20. The slot 20 may extend throughout substantially the entire length of the permit the arm, the outer end of the arm being tapered off at 2| in order to bring the outermost extremity of the slot into the closest possible relation to the interior wall of the conduit The edges of the;- slot 20 have thin forwardly projecting lips 20, as shown in Figure 5, these lips extending almost against the rear wall of the I vertical post 3.

For the purpose of convenience, the sample selecting unit is carried on a base 22 adapted to be positioned against the outside of the conduit the conduit having an opening 23 therein to insertion of the post 3 with its attached parts. The post 3 is carried down below the base to provide a pipe connector portion 24 and the. passage is continued down into this portion 24, the continuation of the passage being designated 5' in Figure 3. A discharge pipe 25 is coupled to the connector portion 24.

On the base 22 is driving mechanism 26 geared to the shaft 6 through a reducing gear 21 and bevel gears 28.

The motor 26 may be continuously driven, although I prefer that it other periodic circuit-closing device of any well known or preferred construction can be connected in circuit with the motor to control its operation. This will be hereinafter more fully described.

When the motor 26 .is not operating the parts occupy the position shown in Figures 3 and 5, the arm |4 being directly behind the post 3 so that the slot 20 is, not openly exposed to the curconduit.

around the interior rent of air and suspended sohds flowing along the pipe. When the motor 26 is operated to drive the shaft 1', the arm I4 is caused to rotate in a circle. In Figure 4 two positions of this arm have been indicated and in both of these positions the arm is not directly behind the post 3.

One position of the arm is shown in full lines one in dotted lines and it may be assumed that the arm is rotating in a clockwise direction,

although this is immaterial. The height of the ;post 3 is such that the axis of the shaft 2 is at the center of the conduit I so that when the arm |4 swings in a circle it will sweep around the entire interior 'ofthe pipe with the tapered portion 2| always close to the inner wall of the The arrangement for driving the motor 26 is referably such that the sampling arm l4 will make one complete revolution and then come to a stop directly behind the post 3 and: remain in such position until the motor 23 is again energized.

'Dlu'lng' the time that the arm i4 is sweeping of the conduit the slot 20 will be exposed to the oncoming stream of fluid the pipe. 23.

duit 2|, suspended particles into the slot 23, through the sleeve portion l5, down the passage 5, and into the extension as is secured a ring :0. Secured to an electric motor or other shall be intermittently operated and for this purpose a time switch or a take samples.

the ring 36 is a bag 31 to the top of which is attached a bolt 38. The bolt 38 passes through the top of the member 3| and is surrounded by a compression spring 39, while a nut and washer, indicated at 40, hold the spring in compression. 5 This arrangement serves to hold the bag 31 taut and at the same time enables the bag to be shaken by jarring the bolt 38. The pipe 25 opens tangentiallyinto the lower part of the member 3| under the deflector 34 so that the current of air circles around the member 34 and the conical extension 35, causing the dust or solid particles to fall into the receptacle 32. The current of air then flows up into the bag 31, where any entrained particles are trapped while the air passes through the bag into the space surrounding the bag and escapes through an outlet 4|. This outlet is shown as having a pressure regulating cap 42 which is adjustable. If it is desirable or necessary to create suction at the outlet 4|, a pipe connection to a suitable pump may be made at this point.

If the pressure in the pipe I is above atmospheric pressure, it will be seen that this flow of air through the pipe will be set up even 25 though the passage 4| opens to the atmosphere rather than to a suction pump.

Before opening the dust collector to remove the sample, the bolt 38 may be jarred to shake the screen or bag 3'! and cause the adhering small particles to fall down into the receptacle 32. The entire sample is thus collected in the receptacle 32 and'when a suflicient amount has been accumulated the dust collector can be opened and the sample removed; 35

The frequency with which the motor 26 will be operated, or rather the frequency at which the arm I 4 will be rotated, will depend upon the nature of the material being sampled and the fre-- quency with which it is desirable or necessary to 0 Only a relatively small sample is removed at each operation so that preferably the container 32 is suflicient to receive the entire sample for a day's run, and before the sample is analyzed the contents of the receptacle 32 are, of course, thoroughly mixed.

In order that the sample will be removed only during the time that the sampling-element is revolving inside the pipe I, a valve 45 is preferably provided in the pipe 25. I have shown this valve as being a common butterfly valve provided with an operating lever 46. A solenoid 41 is provided for operating the valve in one direction, and the solenoid is opposed by a spring 48. The

arrangement is such that when the solenoid is deenergized the valve 45 is closed and when it is energized the valve is open. The solenoid may be in circuit with the motor, as diagrammatically indicated, so that when the 'motor is operating the solenoid 41 will be energized. At this time then so the pipe 25 will be open and the sample can flow through the pipe. When the motor 26 is deenergized the spring 48 functions .to. close the valve; thus. the flow of fluid through the pipe 25 is stopped except when the motor is operating to 55 drive the sampling element. One arrangement for eflecting the timed operation of the motor and causing the arm to be stopped at a predetermined position is diagrammatically illustrated in Figure 6 and will be hereinafter more fully de- 7 scribed.

By reason of the fact that the sampling element is substantially comrtensive with thevradius of the pipe I, and moves in a complete circle\ around the interior or the pipe in a plane trans-' ple selected r the motor,

verse to the direction of the flow of fluid, a samin this manner will be truly representative of the entire stream in the pipe, irrespective of the stratification of the material. The stream is of course deflected from the center of the pipe and to each side of the post E. This portion of the stream is therefore not missed in the selecting of the sample.

The extended Iipportions 20' at each side of the slot 20 serve to assure a more accurate removalof the sample. When a stream-lined surface is placed in a moving stream of fluid, an eddy is set up immediately in front of the streamlined surface where the stream starts to divide, so that the actual division of the stream occurs slightly in advance The thin lips 20, however, projecting forwardly into the stream reach a point where substantially little deflection of the stream has occurred and beyond this point of eddy so that the portion of the stream which is projected into the slot '20) is a substantially normal stream. By reason of the taper of the arm M the flow into the slot 20 is substantially uniform along the entire length of the slot. e

The front end of the shaft i2 has a bearing in a removable stream-lined cap 8a forming a part of the head 8. This cap 8a can be removed for filling the chamber 9 with grease and for giving, access to the mitre gears within the chamber 9. The cap is of course atight-fitting cap, and the bearing at I! is a close bearing so that dust or solid particles cannot work themselves into the chamber 9. In orderto further exclude dust and dirt, a washer may be provided in the chamber 9, this washer being shown at 8b.

To apply the sample removing unit to an air pipe, it is merely necessary to cut a hole in the pipe and secure the base 22 in place by welding or by means of screws, belts or any other con- 4 ventiona'l or desired manner.

Due to the fact that the sample removing ele-' ment I4 is normally behind the post 3, the slot 20 I is not apt to become clogged by the impingement of materials against it when the arm is in-the normal stationary position.

Where a more accurate removal of the sample is desired, the arrangement shown in Figure 6 may be used. In this arrangement the sample selecting unit is mounted on a pipe section 50 adapted to be inserted bodily into the conduit. The pipe section 50 has an annular recess 5| therein, and the sampling arm M is made slightly longer than shown in Figure 3 so that theslot 20 With this actually terminates in the recess 5|. arrangement a more accurate sample of the material flowing immediately adjacent the inner wall of the pipe can be obtained than with the a'rrangement shown in Figure 3 because the end of the slot in the sample selecting arm'may terminate flush with the inside diameter of the pipe, although for most practical purposes the arrangement shown in FigureB is sufliciently accurate.

In Figure 6 I have also shown one arrangement applicable to operating the solenoid and the sampleremoving element at timed intervals and for causing the sample selecting arm M to always be returned to a normal position behind the post l3: In this figure the shaft I is shown as having a downwardly projecting extension la on which is a contact disc conducting materialexcept for onesmall segment at 10. At 1d is a brush that contacts with this disc. The current supply lines are designated A and B. Line B has one lead B leading directly to 'which is a time switch A.

of the stream-lined surface.

portionate to lb, the periphery of which is of and a second lead B" leading to one side of the solenoid 41. Line A has a lead A in I have shown this switch as being of the type inwhich a cam A driven by a clock A periodically closes the switch. 5

The other side of the switch leads to the motor through the wire A Line A- has a second branch or lead A leading to the disc lb. The brush Id connects back to the line A The time operated circuit closer A and ,the motor driven circuit closer Id-4c are thus in parallel. The insulating segment Ic in the disc "lb is so positioned that when the arm M is back of the support 3 the brush id is on this segment and the circuit is open. When the clock A operates to close the switch A the motor is initially energized. This effects a rotation of the contact disc lb so that the circuit will be closed from the line A to the motor through the contact disc lb and the brush 1d. When this condition has arisen, the time switch will open, but the motor will continue to operate ifntil the insulating segment 'Ic again moves around to the brush, at which time both circuit closers will be open and the motor will consequently be deenergized.

The solenoid 41 is shown as being connected in parallel with the motor so that this solenoid is energized while the motor is operating and deenergized when the motor is deenergized.

Instead of selecting samples of solids contained 3 in gases, the invention is also applicable to the sampling of a flowing stream of liquid, and the arrangement shown in Figure 7 may be used for liquids. The sample selecting unit 2 is of the construction shown in Figures 1, 2 and 3 and I have merely shown a reservoir 55 in place of the dust collector 30. The fluid withdrawn as samples collects in the reservoir 55 from whence it may be removed from time to time, which may be necessary or desirable.

In some instances it may be desirable to graduate the intake passage of the collector arm to give increased intake at one point over the intake at another point. More especially, it may be desirable to so construct the intake passage 45 of the collector arm that the material will be taken in increasingly greater amounts from the center out. In Figure 8 one structure for ac-- complishing this is disclosed. The collector arm, designated 6!], is of the construction previously described, but instead of having a continuous intake slot it is provided with a series of slots or openings 6i. These openings are so arranged or designed that there is a relatively greater open space at the outer end of the arm than there is close to the center. The openings 6! are prothe length of the arm and the sample which is collected is more truly represen- 1 ta tive in the proper proportion of the material flowing through the conduit than the sample selector previously described wherein the slot is of continuous Widthand-length. In the construction-shown in Figure 10 a similar result is secured by making the slot of outwardly increasing width. In this figure 62 desig- 65 nates the collector arm and 6315 the intake slot, the edges of which instead ofibeing parallel, are radial. Thus the intake passage is of increasing dimension outwardly. It will be obvious that the intake passages may be otherwise arranged as by being formed of a series of holes differently spaced, and all such modifications and arrangev ments are to be considered the equivalent of the Frequently it is desirable to grade the sample as it is accumulated. This is particularly true of crushed fuel where the proportion of different mesh sizes should be ascertained. For accomplishing this purpose the sample collector, which is of the general type described in connection with'Figure 1, delivers the sample into a series of superimposed screens. In this figure 64 is the separator and 65 designates a series of drawers or compartments having screen bottoms, the screens being of decreasing mesh downwardly, the bottom of the lowest compartment being solid. These screens can be agitated, usually being jolted and reciprocated at the same time. This type of screening mechanism is well-known in the art and for that reason I have not shown the jolting means therefor. The sample which falls into the uppermost tray is sifted and only the coarser particles are retained, while the finer "particles pass through the screen and are successively separated in the succeeding screens.

The apparatus provides an extremely desirable device for securing a sample of suspended particles in a current of air or other gas. Particles are removed from practically every point in the traveling stream so that even if there is stratiflcation in the conduit the sample will be a representative sample of all of the material in the stream. The sweep of the sample arm moving around the interior of the pipe assures this.

The apparatus itself is of simple construction and may be manufactured and installed at a reasonable cost, and secures samples which are much more representative and satisfactory than any sample selecting vided.

I claim:

1. A sampling mechanism adapted to be inserted in a fluid conduit comprising a fixed supporting post having a passageway therein, a rotatable collector arm carried on the post and having an orifice therein, the axis of rotation of the arm being at substantially right angles to the longitudinal axis of the arm, said orifice communicating with the passageway in the post, and

. means for rotating the collector arm.

2. A sampling mechanism adapted to be inserted in a fluid conduit comprising a supporting post having a passageway therein, a rotatable collector arm carried on the post and having an orifice therein, said orifice communicating with the passageway in the post, and means for rotating the collector arm, said collector arm extending radially from the axis of its rotation, the receiving orifice being in the form of a slot extending along the greater portion of the length of the arm.

3. A sampling device adapted to be positioned in a fluid conduit, comprising a supporting post member having a passageway therethrough, a hub member rotatable in the post member and having a passageway therein, a collector arm projecting radially from the hub member and having a receiving orifice therein directed toward the post, said receiving orifice communicating with the passage in thehlib member, the post providing a shield in frontof the slot when the arm is positioned behind the post,-and means for swinging the collecting arm through an arc.

4. A sampling apparatus of the class described, compris ng a supporting structure adapted'to be positioned in a fluid conduit and having a passageway therein; a hub member rotatably carried by the supporting structure, said hub member .being hollow and communicating with the pasmechanism heretofore profrom said passageway in the supporting member.

6. A sampling apparatus of the class described, comprising a supporting member, a collecting arm rotatably carried on the supporting member and adapted to be swung through an arc, means for operating the collecting arm, said collecting arm having a passageway and a receiving orifice therein, said supporting member having a passageway communicating with the passageway in the collecting arm, a pipe leading from said passageway in the supporting member, a collector to which the pipe delivers, a valve in the pipe, and means for effecting an opening and closing action of, the valve. .7. A sampling device adapted to be used in a fluid conduit, comprising a supporting post hav. ing a passageway therein, a hub member rotatably mounted in the post, a collector arm carried on the hub member and extending in a plane transverse to the axis of the hub membr,. said collector arm having a slot extendingthroughout the greater portion of its length and. having a passageway therein communicating with the interior of the hub member, said hub member having a passageway therethrough communicating with the passageway in the supporting member, a gear rigidly connected with the hub meniber to rotate therewith, a drive shaft within the supporting memberand having a gear thereon cooperating with the. said first gear, and driving means operatively connected with said second shaft.

8. In a sampling mechanism, a conduit having an annular internal groove, a supporting member within the conduit, a collecting arm rotatably carried on the supporting member and movable in a circle around the interior of the conduit, means for operating the arm, .said arm having a passageway therein, a conduit in the supporting member with which the passageway in the arm communicates, said arm having a slot extending along it throughout the greater por-.

. tion of its length, the tip of the arm being re-' ceived in the groove on the interior of the con- .duit, the slot extending substantially out to the point adjacent the center ber, a collecting arm carried thereby rotatable C through a circle transverse to the axis of the conduit in which the sampling device is positioned the arm being slightly longer than the inside diameter of the conduit, said conduit being provided with an annular groove to accommodate the arm, said arm having a slot therein extending from'a point adjacent the outer tip of the arm to a point adjacent the inner end thereof, means on the supporting member for rotating the am, said arm and said supporting member havingpassageway in the supporting member terminating at the'elr- 1Q,

teriorof the conduit whereby fluid which enters the slot may be carried from the arm to the supporting member and discharged to a point exteriorly of the conduit.

10. In a sampling mechanism, a conduit of circular cross-section, a supporting member projecting into the conduit, a collector arm rotatably carried by the supporting member, the center of rotation of the arm coinciding with the center of the conduit, said arm and; supporting member having communicating "passageways therein, the wall'of the passageway in the arm having a slot therealong which opens to the interior of the conduit, said supporting member having a portion which projects through an opening in the conduit and terminating in a discharge passage whereby fluidentering the collecting arm maybe discharged outside the conduit, and a valve for controlling the discharge of fluid through said discharge pipe. I v

11. In a sampling mechanism, a conduit of circular cross-section, a supporting member projecting into the conduit, a collector arm rotatably carried by the supporting member, the center of rotation of the arm coinciding with the center of the conduit, said arm and supporting member having communicating passageways therein, the wall of the passageway in the arm having a slot-therealong which opens to the interior of the conduitfsaid supporting member having a portion which projects through an opening in the conduit and terminates in a discharge passage whereby fluid entering the collecting arm may be discharged outside the 'conduit, a valve for controlling the discharge of fluid through said discharge pipe, means outside the conduit for rotating the arm, and means for operating the valve to open position only when said operating means is efiective to rotate the arm.

12. A sampling mechanism adapted for use in a fluid conduit comprising a supporting post having a passageway therein, a radially positioned rotatable collector arm carried on the post in a plane parallel with the post and movable through a plane normal to the direction of flow of fluid through the conduit and having a passageway therein communicating with the pa'ssageway in the post, said passage in the arm opening through the arm to the exterior thereof to permit material in the conduit to flow into the passage in the arm, the open area increasing outwardly from the center of the arm toward the tip. I

13. A sampling apparatus comprising a conduit and a radially positioned collector arm rotatably supported in the conduit for movement in a circle transverse to the longitudinal axis of the conduit, said collector arm being of a length substantially equal to the radius of the conduit, said arm having a passageway extending there- ,along for receiving material from the conduit,

and a conduit into which the arm discharges, said arm having an orifice therethrough through which fluid may flow from the first conduit into the passageway in the arm.

14. A sampling apparatus comprising a conduit and a radially positioned collector arm rotatably supported in the conduit for movement in a circle transverse to the longitudinal axis of the conduit, said collector arm being of a length substantially equal to the radius of the conduit, said arm having a passageway extending therealong for receiving material from the conduit, and a conduit into which the arm discharges, said arm having an orifice therethrough through which fluid may flow from the first conduit into the passageway in the arm, said orifice being in the form of a slot extending throughout the greater portion of the length of the arm.

15. A sampling apparatus comprising a conduit and a radially positioned collector arm ro= tatably'supported in the conduit for movement in a circle transverse to the longitudinal axis of the conduit, said collector arm being of a duit and a collector arm rotatably supported in the conduit for movement in a circle transverse to the longitudinal axis of the conduit, said collector arm being of a length substantially equal to the radius of the conduit, said arm having a passageway extending therealong for receiving material from-the conduit, and a conduit into which the arm discharges, said arm having a series of orifices therethrough at intervals from the outer end of the arm toward the center, the area or the orifices in the arm being greater adjacent the outer end thereof than toward the inner end thereof.

17. A sampling device adapted to be positioned in a fluid conduit, comprising a supporting memried on the supporting member and arcuately movable in a plane transverse to the axis of the fluid conduit and normal to the direction of flow of fluid through the conduit in which the device is positioned, means for efiecting arcuate movement of the collector, said collector having a receiving passageway therein throughout substantially its entire length, and a stationary conduit communicating with said passageway in the collector for receiving fluids from the collector.

18. Sampling apparatus for sampling suspended particles in a fluid medium. comprising in combination a circular conveyor tube section, a sampler supported in said section and movable through a circular path in a plane normal to the longitudinal axis of the section, and means whereby material caught by the sampler is con-- veyed therefrom to the exterior of the conveyor section.

19. A sampling apparatus for removing samples of suspended particles in a gaseous medium, comprising in combination a pneumatic conveyor tube section, a sampler supported in said section and movable through a circular path in a plane normal to the longitudinal axis of the- 

